It is known to dissolve solid polymers in water, by finely dividing the solid polymer and introducing it into water while agitating the water bath. It has been found, however, that some polymers such as polyethylene oxide, used in the cellulose industry as an auxiliary flocculating agent, take a very long time to dissolve, which presents a problem to the achievement of rational procedures.
Consequently, there is a need for a method or an apparatus with which the time taken to dissolve not-readily dissolved polymers can be shortened to one tenth or less of the time taken at present.